In a mobile network, according to a function for which a network element is responsible, the network element maintains a mobile context of user equipment. The mobile context includes information required for serving the user equipment, and the information includes static information, dynamic information, and the like. For example, in a mobility management entity (MME), the mobile context includes: an international mobile subscriber identity (IMSI), an equipment identity (ME Identity), a mobility management context (MM Context), a bearer context (EPS bearer Context), a serving gateway (S-GW) interface identifier and a tunnel endpoint identifier (TED), a capability of supporting features such as idle mode signaling reduction (ISR) and a closed subscriber group (CSG), a time zone in which a terminal is located, and the like. The mobility management context may include a security parameter used for security authentication, such as a security key or an authentication vector, a user equipment bandwidth, or access restriction information. The bearer context may include access point name (APN) information, a user equipment Internet Protocol (IP, Internet Protocol) address, charging information, a bearer identifier, a traffic flow template (TFT), bearer-level quality of service (QoS), and the like.
Multiple network elements of each type may be deployed in the mobile network, and are used for distributed processing or load balancing. When a network element in the mobile network needs to perform a specific service for user equipment, the network element needs to learn in advance of an IP address of a network element serving the user equipment, that is, a network element saving a mobile context of the user equipment, and send, by using a control protocol such as GPRS Tunneling Protocol (GTP), control signaling in which the IP address of the network element is used as a destination IP address, so as to interact with the network element serving the user equipment. To implement operations required in the foregoing procedure, each time a network element is switched, the network element needs to send an address update notification to a related surrounding network element, so that the surrounding network element can update, in a timely manner, addressing information that is of a mobile context of related user equipment and that is saved in the surrounding network element.
In a conventional telecommunication network, a mobile context of user equipment is usually anchored on a specific network element, and addressing information that is of the context of the user equipment and that is saved in a surrounding network element needs to be updated only when switching, maintenance, or load balancing is performed. Therefore, a signaling quality caused during the foregoing configuration and switching procedure is acceptable. However, in a current trend, a function of a network element is virtualized, and the network element is deployed in a data center in a virtual network function (VNF) form. A deployment scenario of a mobile network element in a cloud network challenges the mode in which the mobile context of the user equipment is bound with a specific network element.
Dynamic adjustment requirements of the cloud network such as management, load balance, and power saving may make it common to switch a network element serving user equipment. However, a large amount of signaling exchange across data centers is required for migrating the mobile context of the user equipment between network elements, so that excessive transmission resources of the cloud network are occupied.